Heredity is to-day the central problem of biology. This problem may be approached from many sides—that of the breeder, the experimenter, the statistician, the physiologist, the embryologist, the cytologist—but the mechanism of heredity can be studied best by the investigation of the germ cells and their development.

When I had felt compelled by increasing knowledge of nature to revise some of my traditional articles of religious faith, I was delighted to find that these changes had not modified in any essential respects my system of ethics. As I expressed it in my presidential address before the American Association for the Advancement of Science in 1937:
"The ethics of science regards the search for truth as one of the highest duties of man; it regards noble human character as the finest product of evolution; it considers the service of all mankind as the universal good; it teaches that human nature and humane nurture may be improved, that reason may replace unreason, cooperation supplement competition, and the progress of the human race through future ages be promoted by intelligence and goodwill."

A man of vigorous, definite, judicial, but amiable personality. It seems almost unnecessary to attempt to put into words a characterization of one so well known to zoologists of this country. He is easy to meet, interested in those with whom he comes in contact, and gifted with a good memory for names and faces. A genuine sense of humor crops out unexpectedly to illuminate many a situation, as in his famous remark that 'wooden legs are not inherited, although wooden heads may be' or his equally well-known observation in regard to the anti-evolutionists, 'Apparently the anti-evolutionist expects to see a monkey or an ass transformed into a man, though he must be familiar enough with the reverse process.